Closed captioning allows deaf, hard of hearing, and hearing impaired people to read a transcript of an audio portion of a television, video, or film presentation. As the video is presented to the viewer, text captions are displayed identifying who is speaking, transcribing what is being said, and indicating relevant sounds, such as laughing, crying, crashes, explosions, and the like. Closed captioning is also used to assist people who are learning an additional language, learning to read, or for those in a noisy environment.
For the present disclosure, television, video, and film presentations are referred to as “video,” and the text captions representing the closed captioning of the video are referred to as “closed captioning text.” Closed captioning text is encoded into the video using any number of closed captioning techniques. In many instances, different types of video programming employ different types of closed captioning encoding and decoding.
In North America, National Television Systems Committee (NTSC)-based programming encodes closed captioning text into line 21 of the vertical blanking interval. The vertical blanking interval is a portion of the analog television picture that resides just above the visible portion of the video, and is not seen by the viewer. The viewer's set-top box or television is able to decode the encoded closed captioning text provided in line 21 of the vertical blanking interval and present it to the viewer in association with the video. For digital television, the Advanced Television Systems Committee (ATSC)-based programming encodes three data streams into the video to support closed captioning. One of the streams can support up to 63 unique closed captioning streams, which are encoded in an EIAA-708 format as set forth by the Electronic Industries Alliance (EIA). The other two streams are encoded such that when the digital video is converted to analog video, the closed captioning text appears as encoded closed captioning in line 21 of the vertical blanking interval. Outside of North America, Phase Alternation Line (PAL) and Sequential Color With Memory (SCCAM) video standards transmit and store closed captioning information in a different manner, but the overall result is the same.
Regardless of the encoding and delivery technique, closed captioning is extremely beneficial in providing a transcript of an audio portion of a video program. Unfortunately, closed captioning text is generally only available in one language, although most closed captioning standards support different closed captioning streams for different languages. However, the significant effort and expense associated with providing closed captioning generally limits the closed captioning text to the most prevalent language in which the video will be presented. In the United States, for example, closed captioning is generally only provided in English, even though there are significant Hispanic, Asian, and European contingents who would benefit from closed captioning in their native languages.
Accordingly, there is a need for a way to efficiently and effectively translate closed captioning text presented in a first language into a second language, and make the translated closed captioning text available to viewers of the associated video.